Abstract: In this study, a job scheduling model and task scheduling algorithm-Cost-Optimal Algorithm of Multi-QoS Constraints for Task Scheduling in Hybrid-Cloud (CAMTH) are proposed to solve the task scheduling problem for hybrid cloud. In the job scheduling model, a hybrid cloud agent which acts as a mediator between clients and public cloud resources is presented to facilitate choosing the candidate service that has the most appropriate price and higher quality level. The proposed CAMTH is divided into three steps, namely task scheduling of private cloud, service selection and task scheduling of public clouds. In addition, CAMTH supports security and reliability under conditions of QoS constraints, in order to select the optimal price public cloud resources on the basis of the eligible conditions. In order to prove the functionality of the proposed algorithm, several experiments are carried out. Experimental result shows that CAMTH algorithm achieves a better balance with waiting time, executing time, QoS satisfaction and execution cost.